STAFF
Mikha Diaz
EXECUTIVE DIRECTOR
After a first career as a Philosophy professor, and a second career as a small bar and restaurant owner, Mikha joined Xenophon in 2024 as Executive Director. Inspired by her transformative relationship with her own horse, and her deep belief in the therapeutic power of equine engagement, Mikha joined Xenophon to support its continued growth and development.
A Northern California gal by birth, Mikha lived in London, Boston and New York before returning home – first to San Francisco, and then Berkeley, before finally settling in Walnut Creek with her husband, Edwin, their daughter, Ana, their dog, Rosie, and their horses, Serafina and Billy. When not at the barn or out on a trail, Mikha enjoys cooking and entertaining at home, and watching Ana ride…here, there and everywhere!
Danielle Coburn
PROGRAM DIRECTOR
Danielle grew up in Danville, attended Seven Hills, Athenian and Pepperdine University. Prior to being involved with therapeutic riding, she spent many years working in the fashion industry at Nordstrom, followed by working as a sales rep and then in management for international watch companies. Danielle began riding at the age of 6 and was instantly bit by the “horse bug”. She took riding lessons and trained as a hunter/jumper in the Tassajara Valley.
Danielle first became involved in therapeutic riding in 2006 when she began volunteering and teaching at SonRise Equestrian Foundation. Seeing the magical connection special needs children had with the horses was magnetic to her, and from then on she was hooked on the concept. She began at Xenophon in 2010 and received her PATH Registered Therapeutic Riding Instructor Certification in 2011. Being a part of Xenophon combines her two passions: children and horses.
When Danielle isn’t at Xenophon, she volunteers her time with the San Ramon Valley Horsemen’s Association, the Equestrian Center of Walnut Creek, and is a member of Soroptimist International of 24/680 Walnut Creek. Danielle enjoys traveling, spending time with her family, friends, her dog Mattie, and her horse Dandie who retired from Xenophon in 2014.
Rebecca Wernicke
VOLUNTEER COORDINATOR
Rebecca grew up riding in Los Angeles and Orange County, showing in hunters and equitation. She competed for the UC Berkeley IHSA team while working as a catch rider in the East Bay, rehabbing older horses and bringing along green horses. After graduating with a BA in History with a focus on Environmental History, Rebecca continued on to train horses and teach professionally, teaching hunter/jumper riders up to 3’6”. She has dabbled in many disciplines including dressage, endurance, eventing, western, trail, vaulting, sidesaddle, and natural horsemanship. Rebecca volunteered at Ride Your Horse! TRC in Cerritos while in high school and returned to her passion in 2019 at Xenophon Therapeutic Riding Center. She then followed her dream of becoming a Certified Therapeutic Riding Instructor with PATH Intl., teaching at both Xenophon and Giant Steps Therapeutic Equestrian Center in Petaluma.
On weekends you can find her obsessing over her cat Connie, reading vampire novels, and looking for the best cheeseburger in Oakland.
Bria Gutierrez
COMMUNICATIONS & ADMINISTRATIVE ASSISTANT
From collecting horse figurines to participating in pony summer camp, Bria fell in love with horses and riding as a young girl. Life experiences like school, university, and establishing a career had her taking breaks from being around horses, but she always managed to find her way back to riding lessons periodically. Bria moved up to the East Bay at the beginning of 2025 after living in Orange County for a few years and riding in a Hunter/Jumper lesson program in Anaheim. She was quick to join a new Hunter/Jumper lesson program in Sunol to continue her riding. She is ecstatic to be a part of the Xenophon team to combine her professional background in social media management and content strategy with her passion for the equine industry. Bria is furthering her equine education through earning a diploma in Equine Studies online from University of Guelph.
Outside of work, Bria enjoys seeking out the best iced matcha latte, spending time with her boyfriend and two dogs, touring Victorian homes, and baking vegan desserts.
Laura Presmyk
BARN MANAGER
THERAPISTS
Lisa Dominiak
OCCUPATIONAL THERAPIST
Lisa grew up in the Bay Area and attended San Jose State University, graduating with a degree in Occupational Therapy. She has worked as an Occupational Therapist for over 20 years and was drawn to pediatrics early in her career. After having worked in local hospitals like UCSF Children’s Hospital Oakland and John Muir Medical Center, Lisa currently works in a pediatric outpatient setting in addition to being an Occupational Therapist at Xenophon.
Lisa discovered the “magic” of horses in more recent years and is so glad she did. “To combine the movement of these beautiful animals with the work that I love is very special. I am so happy to be a part of this program.”
Lisa is also a certified yoga teacher and enjoys bringing her mindful movement training into her therapy sessions. In her free time she enjoys spending time with friends and family, practicing yoga, and Taiko drumming.
Rachel Levy
OCCUPATIONAL THERAPIST
Rachel was born and raised in the Bay Area. She obtained her bachelor’s degree from UC Santa Cruz and continued her education at Samuel Merritt University where she received her Doctorate in Occupational Therapy. Rachel has always had an affinity for working with children and is so thankful to do so with Xenophon in addition to her school-based occupational therapy work in West Contra Costa.
Rachel has fond memories of riding horses with her grandma as a child. However, it was not until she began working with Xenophon in 2023 that she truly understood the immense benefits of being with horses.
When not working, Rachel can be found with clay covered hands at her ceramics studio, hiking in the redwoods, or playing guitar and singing to her partner and their cat.
Melissa Maker
PHYSICAL THERAPIST ASSISTANT
Melissa is a true local girl, having grown up in the Orinda area. She has been volunteering/working at Xenophon for 18 years. Melissa got started as a volunteer –– first sidewalking, then becoming a horse handler. She began teaching for Xenophon in 2000, became a PATH Certified Registered Instructor in 2003, and completed her training as a Physical Therapist Assistant in 2015. Melissa has been riding most of her life, participating in pony club and then going on to compete in dressage and 3-day eventing. Her talented equestrian skills led her to become a riding instructor in her teens and she has continued since that time.
Outside of Xenophon, Melissa enjoys playing tennis, skiing, and running agility with the Australian Shepherds in her life, Luke and Blue.
INSTRUCTORS
Lindsay Donahue
CERTIFIED THERAPEUTIC RIDING INSTRUCTOR
Lindsay grew up on an island…Alameda! Lindsay graduated from California State East Bay with a BS in Kinesiology, followed by the achievement of a Single Subject Teaching Credential for grades 1-12 and adult school.
In 2011, a friend introduced Lindsay to Xenophon. The idea of a program that used horses as a therapy model for students with disabilities spoke to her and Lindsay has been with Xenophon ever since. She started as a sidewalker, became a groom, and then moved on to horse handler. In 2016, Lindsay was awarded the Jean Schaffner Spirit Award for outstanding volunteer at Xenophon, and then was recognized by PATH International as the Volunteer of the Year for Region 11.
In 2017, Lindsay decided to become an instructor under the mentorship of Mari Parino, Xenophon’s Executive Director at the time. Lindsay not only teaches therapeutic riding lessons, but also works with our Camp Alumni program. Lindsay can also be found volunteering on other days with Xenophon and is an integral part of the center –– Xenophon holds a special place for her.
Patti Dreyer
CERTIFIED THERAPEUTIC RIDING INSTRUCTOR
Laura Fend
INSTRUCTOR
Laura graduated from Cal Poly with a degree in Child Development. She went on to get her teaching credential from St. Mary’s College, and spent 15 years teaching elementary school in both the Mt. Diablo and Walnut Creek School Districts. Laura began volunteering for Xenophon over 15 years ago and it was here she found her true love: teaching therapeutic riding, which combines her love for horses and children.
Laura has been involved in the horse world for over 40 years. She is an active competitor in endurance riding, along with her husband Gary of 42+ years. She currently serves as the pasture manager for the Moraga Horseman’s Association, having served as president of both that organization and the San Ramon Valley Horseman’s Association.
Laura enjoys working in the yard and restoring her 100+ year old house, as well as spending time with her two children, grandchildren, dogs, and chickens. She also enjoys camping in the mountains and spending time at the beach.
Haley Mathews
CERTIFIED THERAPEUTIC RIDING INSTRUCTOR; VETERANS FACILITATOR - OPERATION HOOVES ON THE GROUND
Haley grew up riding horses on her family’s cattle ranch in San Ramon. She graduated from Cal Poly San Luis Obispo with a degree in Agricultural Science with a concentration in horses. Right out of college she worked with at-risk high school students in various countries and Hawaii for three years. Haley also worked as the Assistant Director of Shepherd’s Gate in Livermore, a homeless shelter for women and children, for 12 years.
In 2008, Haley became involved with therapeutic riding at SonRise Equestrian in Castro Valley where she continues to teach riding lessons. The beautiful connection between the horse and the child is what Haley loves most about therapeutic riding. She has since received her PATH certification in 2014 and joined the Xenophon team in January 2015 where she now also works as the Veterans Facilitator for our veterans program, Operation Hooves on the Ground.
When not teaching riding and horsemanship lessons, Haley works at her family’s commercial real estate business and manages the cattle ranch in San Ramon where she and her husband, Brian, live. She loves walking on the ranch with her two dogs Max and Zorro.
Jen Wineman
CERTIFIED THERAPEUTIC RIDING INSTRUCTOR
Jen grew up in the central valley of California on a vineyard. After graduating from nursing school and then nurse practitioner school, she worked for 20 years as a Primary Care Pediatric Nurse Practitioner in Alameda and Oakland. Jennifer found her way to Xenophon in 2017 in pursuit of a deeper understanding of adaptive riding as a therapy modality for neurodiverse children. She began volunteering, first as side walker, then as a groom and horse handler. She loved the work so much that in 2018, she quit her job as a Pediatric Nurse Practitioner and decided to become a Therapeutic Riding Instructor. In 2020, she completed the certification process and began teaching at Xenophon.
As a child, Jen rode a beautiful Palomino named Gypsy and all these years later, she found horses again. She says that Xenophon combines her two great loves, children and horses. “It was like coming home.”
When not at Xenophon, Jen can be found running, riding her bike, riding Dandelion at Summit Ranch, or walking her dog Wally with her husband Matt.
Sierra Zettlemoyer
INSTRUCTOR